The Pareto chart is a statistical tool used to identify and prioritize the main causes of failures in a process. It is based on the Pareto Principle (80/20), which states that about 80% of problems come from 20% of causes.
When applied to test engineering and production, the Pareto allows highlighting the so-called Top Failures — the most recurring or impactful failure modes in a batch, product, or process.
Why use Pareto in testing?
- Focus on the most relevant causes of failure
- Targeted and efficient process improvement
- Reduction of rework and analysis time
- Support for corrective actions based on real data
- Support in audits, certifications, and quality management
How does the Pareto chart work?
A Pareto chart consists of:
- A descending histogram showing the frequency (or impact) of each failure
- A cumulative curve (%) that helps visualize the relative weight of the causes
Example:
| Type of failure | Occurrences | % Cumulative |
|---|---|---|
| Firmware failure | 120 | 40% |
| Short between pins | 80 | 67% |
| Poorly fitted connector | 50 | 84% |
| Current out of range | 30 | 94% |
| Host communication failed | 10 | 100% |
In this case, 3 types of failures represent 84% of occurrences, being considered Top Failures.
Practical application with AJOLLY Testing
AJOLLY Testing incorporates Pareto analysis and Top Failures detection in its testing and validation projects, focusing on efficiency, traceability, and continuous improvement.
🔍 Automated data collection
- Recording of failure codes by serial number
- Association by station, operator, product, batch, or shift
- Standardized categorization of failures in test software
📊 Automatic report generation
- Pareto charts in real-time via dashboards
- Export to Excel, PDF, or integration with MES / ERP
- Visualization by period, product, firmware version, etc.
🛠️ Support for corrective action
- Identification of critical failures for the client or process
- Development of action plans based on Top Failures
- Monitoring the effectiveness of implemented improvements
Benefits of Pareto analysis with AJOLLY Testing
- Greater focus of the technical team on the failures that have the most impact
- Reduction of NDFs (No Defect Found) and false negatives
- Decision support with real and traceable data
- Quality documentation oriented for audits
- Continuous improvement based on evidence, not assumptions